The invention relates to a feed and guide mechanism which is rigidly secured to a linearly moving breech mechanism of an automatic gun barrel weapon.
Such type of feed and guide mechanisms is already known and described in U.S. Pat. No. 4,167,888. In this known automatic weapon with external drive motor there is provided a gun barrel whose axis is fixed with respect to a breech casing. A cartridge chamber is disposed rearwardly of the gun barrel and is adapted to coact with a breech mechanism. A rotary drum, whose peripheral surface has helical grooves forming a drive ramp of closed contour, is mounted in the breech casing. A follower member cooperates with the drive ramp and is rigidly connected to the breech mechanism. The arrangement includes two rods disposed above the rotary drum parallel to the longitudinal gun barrel axis and serve for guiding the breech mechanism in a nonuniform manner for counter recoil and recoil movements. The follower member is constructed as a rotatable plate mounted on the breech mechanism, which supports in a plane two rotatable rollers for coaction with the drive ramp disposed on the rotary drum. There are disposed on this plate at least two flat guide surfaces for the alternate coaction with at least one also flat guide surface disposed on the housing or breech casing. Thereby the two rollers mounted on the plate are specifically aligned in the cross-over region of the control groove so that the follower can traverse without malfunctioning. The rotary drum carries out a firing cycle in n revolutions, whereby n is at least equal to 3, but advantageously is equal to 4. Thereby there results n-1 cross-over regions for different branches of the drive ramp.
This known arrangement has the following drawbacks:
It requires first of all a considerable height in view of two cross-over regions per firing cycle. An additional guiding in the housing is required on corresponding sections of the breech path for the plate which is rotatably mounted on the breech body. Consequently, a mounting adjustment in a delayed manner is necessary. Additionally the feed forces are introduced via the support shaft of the plate unilaterally into the breech mechanism and, as a result of the ensuing increased wear caused by friction, malfunctioning may occur. Finally, the firing bolt arranged in the breech body is disadvantageously inertially actuated and consequently must have a sufficiently large mass which is a further drawback to be considered.